threadvar.h

/* Internal per-thread variables for the Hurd. Copyright (C) 1994,95,97,98,99,2001,02,06,07 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */#ifndef _HURD_THREADVAR_H#define _HURD_THREADVAR_H#include <features.h>/* The per-thread variables are found by ANDing this mask with the value of the stack pointer and then adding this offset. In the multi-threaded case, cthreads initialization sets __hurd_threadvar_stack_mask to ~(cthread_stack_size - 1), a mask which finds the base of the fixed-size cthreads stack; and __hurd_threadvar_stack_offset to a small offset that skips the data cthreads itself maintains at the base of each thread's stack. In the single-threaded case, __hurd_threadvar_stack_mask is zero, so the stack pointer is ignored; and __hurd_threadvar_stack_offset gives the address of a small allocated region which contains the variables for the single thread. */externunsignedlongint __hurd_threadvar_stack_mask;
externunsignedlongint __hurd_threadvar_stack_offset;
/* A special case must always be made for the signal thread. Even when there is only one user thread and an allocated region can be used for the user thread's variables, the signal thread needs to have its own location for per-thread variables. The variables __hurd_sigthread_stack_base and __hurd_sigthread_stack_end define the bounds of the stack used by the signal thread, so that thread can always be specifically identified. */externunsignedlongint __hurd_sigthread_stack_base;
externunsignedlongint __hurd_sigthread_stack_end;
externunsignedlongint *__hurd_sigthread_variables;
/* At the location described by the two variables above, there are __hurd_threadvar_max `unsigned long int's of per-thread data. */externunsignedint __hurd_threadvar_max;
/* These values are the indices for the standard per-thread variables. */enum __hurd_threadvar_index
{
_HURD_THREADVAR_MIG_REPLY, /* Reply port for MiG user stub functions. */
_HURD_THREADVAR_ERRNO, /* `errno' value for this thread. */
_HURD_THREADVAR_SIGSTATE, /* This thread's `struct hurd_sigstate'. */
_HURD_THREADVAR_DYNAMIC_USER, /* Dynamically-assigned user variables. */
_HURD_THREADVAR_MALLOC, /* For use of malloc. */
_HURD_THREADVAR_DL_ERROR, /* For use of -ldl and dynamic linker. */
_HURD_THREADVAR_RPC_VARS, /* For state of RPC functions. */
_HURD_THREADVAR_LOCALE, /* For thread-local locale setting. */
_HURD_THREADVAR_CTYPE_B, /* Cache of thread-local locale data. */
_HURD_THREADVAR_CTYPE_TOLOWER, /* Cache of thread-local locale data. */
_HURD_THREADVAR_CTYPE_TOUPPER, /* Cache of thread-local locale data. */
_HURD_THREADVAR_MAX /* Default value for __hurd_threadvar_max. */
};
#ifndef _HURD_THREADVAR_H_EXTERN_INLINE#define _HURD_THREADVAR_H_EXTERN_INLINE __extern_inline#endif/* Return the location of the value for the per-thread variable with index INDEX used by the thread whose stack pointer is SP. */externunsignedlongint *__hurd_threadvar_location_from_sp
(enum __hurd_threadvar_index __index, void *__sp);
_HURD_THREADVAR_H_EXTERN_INLINE unsignedlongint *
__hurd_threadvar_location_from_sp (enum __hurd_threadvar_index __index,
void *__sp)
{
unsignedlongint __stack = (unsignedlong int) __sp;
return &((__stack >= __hurd_sigthread_stack_base &&
__stack < __hurd_sigthread_stack_end)
? __hurd_sigthread_variables
: (unsignedlongint *) ((__stack & __hurd_threadvar_stack_mask) +
__hurd_threadvar_stack_offset))[__index];
}
#include <machine-sp.h>/* Define __thread_stack_pointer. *//* Return the location of the current thread's value for the per-thread variable with index INDEX. */externunsignedlongint *
__hurd_threadvar_location (enum __hurd_threadvar_index __index) __THROW
/* This declaration tells the compiler that the value is constant given the same argument. We assume this won't be called twice from the same stack frame by different threads. */
__attribute__ ((__const__));
_HURD_THREADVAR_H_EXTERN_INLINE unsignedlongint *
__hurd_threadvar_location (enum __hurd_threadvar_index __index)
{
return __hurd_threadvar_location_from_sp (__index,
__thread_stack_pointer ());
}
#endif /* hurd/threadvar.h */